Optical devices are commonly used in various environments to enhance the capabilities of the user's vision. In military environments, various optical devices are used to give a soldier enhanced visibility in harsh conditions. For example, devices like the PVS 14 night vision monocular are commonly used in the military to enhance a soldier's visibility in low light conditions. These optical devices are affixed to combat helmets, weapons, or other structures that a soldier uses, and during a field operation, a soldier may move the optical device between the various mounting structures.
The use of a shoe to secure an optical device to a mounting structure, such as a combat helmet or a weapon, is well-known in the art. FIGS. 1-3 are illustrations of an optical device mounting system, in accordance with the prior art. As is shown, the optical device 10 has a mounting shoe 20 secured thereto, such as with fastener 22. A pocket 30 is formed within the mounting shoe 20 (FIG. 1). The mounting shoe 20 engages with a receiver 40 of a mounting structure 50, as may be positioned on a combat helmet or weapon. A locking arm 60 protrudes into the receiver 40 such that when the mounting shoe 20 is engaged with the receiver 40, the locking arm 60 engages with the pocket 30 to securely retain the mounting shoe 20 within the receiver 40. To disengage the mounting shoe 20 from the receiver 40, the locking arm 60 may be withdrawn from engagement with the pocket 30, such as with buttons 70.
The optical device mounting system shown in FIGS. 1-3 is one type of mounting system—many others exist within the art. The shoe may have various designs, depending on the mounting structure the optical device is mounted to, and it is beneficial for the various designs of the shoe to be interchangeable with different mounts. There are two main types of conventional shoes: a shoe for engagement with a butterfly clip commonly used to mount optical devices to weapons; and a shoe 30 with a pocket, commonly used to mount optical devices to a combat helmet. Both types of conventional shoes are static, unitary structures with a dovetail shape and a plurality of angled sidewalls which allow the shoe to engage with a receiver. The shoe for engagement with the butterfly clip utilizes an angled back surface, such as a 10° angle along the edge at the wide end of the dovetail shape, to engage with a butterfly clip when the shoe is inserted in to the mounting receiver. The shoe with the pocket is secured within the mounting receiver with a retractable locking mount which moves into the pocket to engage with the shoe.
While both types of shoes have been used for some time, manufacturing a shoe that is successful with both the butterfly clip engagement and the pocket engagement has proved difficult. The shoe must be manufactured with extremely precise tolerances to allow the shoe to engage with the mounting receiver properly. Often times, a shoe with both types of engagement may fit with the butterfly clip but not fit with the pocket, or vice versa. It is often difficult for manufactures to control the tolerances needed for the butterfly clip engagement, and failing to do so can prevent proper mounting of the optical device. For example, if the tolerance between the angled edge of the shoe and the butterfly clip is too large, the shoe may be too loose within the mounting receiver, whereas if the tolerance is too small, the shoe may not lock within the mounting receiver at all, or the butterfly clip may become jammed and not allow the shoe to be released.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.